I don't know how you would really calibrate Kj. Best case, it's a really bad estimate. Even if you somehow calculate it using a power meter, it's going to be a pretty bad estimate. Sort of like Strava's power estimate, I swear it's low even when I have a tailwind. I have a power meter, but it doesn't do ant+ so I have to compare.

I looked at the elemnt google group, and some of the things worried me a little. However, for my application, which doesn't involve any sensors, it seems to work pretty well. And feel like they will keep working on the issues, maybe some of the people with older sensors will be out of luck though.

I saw a post today from someone selling a garmin touring for $20. They said that they didn't want to sell it to anyone they liked. Someone responded that they thought Garmin support was going to hang up on them when they were seeking help with their 820. The answer was, "out of warranty." Heh.